Fetal Heart Rate Monitoring Research Articles

Implementation of a revised classification for intrapartum fetal heart rate monitoring and association to birth outcome: Anational cohort study.

A revised intrapartum cardiotocography (CTG) classification was introduced in Sweden in 2017. The aims of the revision were to adapt to the international guideline published in 2015 and to adjust the classification of CTG patterns to current evidence regarding intrapartum fetal physiology. This study aimed to investigate adverse neonatal outcomes before and after implementation of the revised CTG classification. A before-and-after design was used. Cohort I (n=160210) included births from June 1, 2014 through May 31, 2016 using the former CTG classification, and cohort II (n=166558) included births from June 1, 2018 through May 31, 2020 with the revised classification. Data were collected from the Swedish Pregnancy and Neonatal Registers. The primary outcome was moderate to severe neonatal hypoxic ischemic encephalopathy (HIE 2-3). Secondary outcomes were birth acidemia (umbilical artery pH <7.05 and base excess < -12mmol/L or pH <7.00), A-criteria for neonatal hypothermia treatment, 5-min Apgar scores <4 and <7, neonatal seizures, meconium aspiration, neonatal mortality and delivery mode. Logistic regression was used (period II vs period I), and results are presented as adjusted odds ratios (aORs) with 95% confidence intervals (95% CIs). There were no statistically significant differences in HIE 2-3 (aOR 1.27; 95% CI 0.97-1.66), proportion of neonates meeting A-criteria for hypothermia treatment (aOR 0.96; 95% CI 0.89-1.04) or neonatal mortality (aOR 0.68; 95% CI 0.39-1.18) between the cohorts. Birth acidemia (aOR 1.36; 95% CI 1.25-1.48), 5-min Apgar scores <7 (aOR 1.27; 95% CI 1.18-1.36) and <4 (aOR 1.40; 95% CI 1.17-1.66) occurred more often in cohort II. The absolute risk difference for HIE 2-3 was 0.02% (95% CI 0.00-0.04). Operative delivery (vacuum or cesarean) rates were lower in cohort II (aOR 0.82; 95% CI 0.80-0.85 and aOR 0.94; 95% CI 0.91-0.97, respectively). Although not statistically significant, a small increase in the incidence of HIE 2-3 after implementation of the revised CTG classification cannot be excluded. Operative deliveries were fewer but incidences of acidemia and low Apgar scores were higher in the latter cohort. This warrants further in-depth analyses before a full re-evaluation of the revised classification can be made.

Ultrasound characteristics and pregnancy loss in bovine IVF-derived pregnancies

We compared ultrasound characteristics during the first trimester of Girolando female bovine IVF gestations that reached term or not. Pregnant recipients (n = 35) were followed up by ultrasonography every 6 days from D37 up to D90 or until the fetal heartbeat ceased. Embryonic vesicle diameter (EVD), fetometry parameters crown rump length (CRL) and biparietal diameter (BPD), and fetal heart rate (FHR) were assessed in fetuses from recipients that completed gestational development (n = 30) (Control group) or experienced pregnancy loss (n = 5) (Pregnancy Loss group). Results were analyzed by ANOVA repeated measurements. A detection of embryonic vesicle was not possible at D31 in gestations that did not reach term. CRL was decreased in pregnancy loss group and differed at D37 (16.17 ± 0.30 vs 13.14 ± 0.77 mm, for control and pregnancy loss group, respectively) and D55 (46.13 ± 0.51 vs 41.88 ± 2.74 mm, for control and pregnancy loss group, respectively). BPD values were similar between groups. FHR decreased at D49 (181.52 ± 0.82 vs 164.75 ± 9.29 bpm, for control and pregnancy loss group, respectively) and D55 (175.41 ± 2.19 vs 150.80 ± 15.10 bpm, for control and pregnancy loss group, respectively) in early pregnancy losses. These findings indicate that embryonic vesicle, CRL and FHR monitoring of IVF-derived gestations at days 31, 37 and 55 could be useful to predict an increased risk of pregnancy loss.

Strengthening Fetal Heart Rate Monitoring during Labor with a Standard Handheld Doppler - Implementation Experience from India.

India's neonatal and perinatal mortality is among the highest in the world. Intrapartum-related conditions contribute to a significant proportion of neonatal deaths and stillbirths. Fetal heart rate monitoring, a recommended norm to assess fetal well-bring, is not practiced as per standard guidelines in public health facilities. A standardized Doppler along with training on fetal heart rate monitoring was implemented across different levels of healthcare in three states. Facilities were selected purposively to implement the Doppler. Baseline data for 3 months were collected. Interviews of health providers and observation of labor were conducted quarterly. Data were analyzed through a comparison of baseline and intervention on a number of delivery and monitoring indicators. Among 22,579 total deliveries, monitoring frequency increased along with increase in detection of abnormal fetal heart rate (FHR) while cesarean section and stillbirths reduced slightly. Cases never monitored reduced in the District Hospitals (7.98-2.07, P < 0.01) and in Community Health Centers (14.7-1.67, P < 0.001). Stillbirth rate reduced at the medical college (3.6-1.1, P < 0.001). Interviews with providers revealed acceptance of the device due to its reliable readings. The Doppler demonstrates acceptability and serves as a useful aid to improve intrapartum FHR monitoring.

A Multi-Layer Hybrid Network With Its Application in Fetal Heart Rate Monitoring

A Multi-Layer Hybrid Network With Its Application in Fetal Heart Rate Monitoring

Machine Learning Model for Classifying the Results of Fetal Cardiotocography Conducted in High-Risk Pregnancies.

PurposeFetal well-being is usually assessed via fetal heart rate (FHR) monitoring during the antepartum period. However, the interpretation of FHR is a complex and subjective process with low reliability. This study developed a machine learning model that can classify fetal cardiotocography results as normal or abnormal.Materials and MethodsIn total, 17492 fetal cardiotocography results were obtained from Ajou University Hospital and 100 fetal cardiotocography results from Czech Technical University and University Hospital in Brno. Board-certified physicians then reviewed the fetal cardiotocography results and labeled 1456 of them as gold-standard; these results were used to train and validate the model. The remaining results were used to validate the clinical effectiveness of the model with the actual outcome.ResultsIn a test dataset, our model achieved an area under the receiver operating characteristic curve (AUROC) of 0.89 and area under the precision-recall curve (AUPRC) of 0.73 in an internal validation dataset. An average AUROC of 0.73 and average AUPRC of 0.40 were achieved in the external validation dataset. Fetus abnormality score, as calculated from the continuous fetal cardiotocography results, was significantly associated with actual clinical outcomes [intrauterine growth restriction: odds ratio, 3.626 (p=0.031); Apgar score 1 min: odds ratio, 9.523 (p<0.001), Apgar score 5 min: odds ratio, 11.49 (p=0.001), and fetal distress: odds ratio, 23.09 (p<0.001)].ConclusionThe machine learning model developed in this study showed precision in classifying FHR signals. This suggests that the model can be applied to medical devices as a screening tool for monitoring fetal status.

Maternal Facial Nerve Palsy and a Perinatal Infection.

Maternal Facial Nerve Palsy and a Perinatal Infection.

Intrapartum fetal heart rate monitoring and offspring long-term neurological health

Although some evidence suggests that intrapartum fetal heart rate (FHR) monitoring is associated with a reduction in intrapartum death, a reduction in long-term neurological impairment or cerebral palsy (CP) has not been proven. However, continuous intrapartum FHR monitoring resulted in more cesarean deliveries (CDs) for abnormal FHR patterns. In this study, we sought to evaluate offspring long-term neurological morbidity of children born via CD for non-reassuring FHR (NRFHR) indication as compared with non-progressive labor (NPL)

Assessing the feasibility of long term home electrophysiological fetal heart rate monitoring

Assessing the feasibility of long term home electrophysiological fetal heart rate monitoring

Validation of a new electrophysiological fetal heart rate monitor: comparison with cardiotocography

Validation of a new electrophysiological fetal heart rate monitor: comparison with cardiotocography

Relationship between Twin-to-Twin Selective Intrauterine Growth Restriction with sFas/sFasL Level of Umbilical Cord Blood Using Doppler Ultrasound Fetal Heart Rhythm Detection Algorithm

The study focused on the application value of ultrasound Doppler fetal heart rate detection algorithm based on short-time Fourier transform (STFT) in the diagnosis of twin-to-twin selective intrauterine growth restriction (sIUGR) and the correlation between twin-to-twin sIUGR and sFas/sFasL levels of umbilical cord blood. The normalized method was introduced into the STFT algorithm to optimize it to detect the fetal instantaneous heart rate. 82 pregnant women with twin pregnancies were selected as the research subjects and they were divided into the restricted group (41 cases) and the control group (41 cases) according to whether the fetus had selective growth restriction. The two groups were compared for the differences in the fetal mortality, complication rate, and sFas/sFasL expression levels. The results showed that the STFT-based ultrasonic Doppler fetal heart rate detection algorithm could ensure the quality of the fetal heart rate signal and had high resolution at the 200–400 Hz characteristic frequency band and that the accuracy in distinguishing S1 and S2 was 5.8% higher than that of the traditional autocorrelation algorithm. The proportion of abnormal fetal heart rate in the restricted group was significantly higher than that in the control group ( P &lt; 0.05 ), birth weight was significantly lower than that in the control group ( P &lt; 0.05 ), and fetal mortality was significantly higher than that in the control group ( P &lt; 0.05 ). There was no statistical difference in the incidence of complications between the two groups ( P &gt; 0.05 ). In restricted group, the content of sFas in cord blood was (3326.54 ± 317.42) pg/mL and that in the control group was (2003.29 ± 196.45) pg/mL. The content of sFas in cord blood of the restricted group was significantly higher than that of the control group ( P &lt; 0.01 ). In the restricted group, the content of sFasL in cord blood was (382.52 ± 36.17) pg/mL, and that in the control group was (180.84 ± 16.20) pg/mL. The content of sFasL in cord blood of the restricted group was significantly higher than that of the control group ( P &lt; 0.001 ). It was concluded that the STFT-based ultrasound Doppler fetal heart rate monitoring is beneficial to early diagnosis and timely intervention of twin-to-twin sIUGR.

Relationship Between Umbilical Cord Gas Values and Neonatal Outcomes: Implications for Electronic Fetal Heart Rate Monitoring.

Relationship Between Umbilical Cord Gas Values and Neonatal Outcomes: Implications for Electronic Fetal Heart Rate Monitoring.

Fever after Preterm Prelabor Rupture of Membranes.

Fever after Preterm Prelabor Rupture of Membranes.

Abstract 9355: Home Monitoring to Detect Emergent Anti-Ro/SSA Antibody Mediated Fetal Av Block: Preliminary Results of the STOP BLOQ Study

Introduction: Fetal complete AV block (CAVB), complicates 2% of anti-Ro antibody positive pregnancies and carries substantial perinatal morbidity and mortality. Anti-inflammatory treatment of 1° and 2° (emergent) AVB may prevent progression to CAVB, yet the optimal surveillance strategy to detect emergent CAVB is unknown. Methods: We examined participants in a multicenter, open label clinical trial of pregnancies risk stratified by anti-Ro antibodies into high (≥1000 IU) or low (&lt;1000 IU) titers. Low titer mothers were followed by echocardiograms or routine OB care; high titer mothers underwent 3x/day fetal heart rate monitoring (FHRM) and weekly or biweekly fetal echocardiograms from 17-26 weeks. If mothers suspected abnormal FHRM, they texted fetal heart sounds to cardiologist, who assessed FHRM and reassured or referred for emergency fetal echocardiogram (performed in &lt; 6 hours). Postnatal electrocardiograms (ECG) were evaluated. Results: Sixty-five subjects from 7 centers were recruited and 60 (92%) enrolled at 14 (5-19) weeks. There were 24 (40%) low titer and 36 (60%) high titer mothers. High titer mothers underwent FHRM; 92% completed FHRM and 100% completed surveillance echocardiograms. Of 3,360 FHRM recordings, mothers texted 39 (1%) recordings of concern; cardiologist deemed 2/39 (5%) as abnormal and emergency echocardiograms revealed atrial ectopy. No fetus developed emergent or CAVB. Postnatal ECGs demonstrated normal AV conduction in all neonates: 2 miscarried at &lt;12 weeks and 48 are in utero. Conclusion: These data support FHRM in the surveillance of anti-Ro antibody positive pregnancies because of high enrollment, feasibility, and accuracy in arrhythmia detection.

An integrated approach based on advanced CTG parameters and Doppler measurements for late growth restriction management

BackgroundThe clinical diagnosis of late Fetal Growth Restriction (FGR) involves the integration of Doppler ultrasound data and Fetal Heart Rate (FHR) monitoring through computer assisted computerized cardiotocography (cCTG). The aim of the study was to evaluate the diagnostic power of combined Doppler and cCTG parameters by contrasting late FGR –and healthy controls.MethodsThe study was conducted from January 2018 to May 2020. Only pregnant women who had the last Doppler measurement obtained within 1 week before delivery and cCTG performed within 24 h before delivery were included in the study. Two hundred forty-nine pregnant women fulfilling the inclusion criteria were enrolled in the study; 95 were confirmed as late FGR and 154 were included in the control group.ResultsAmong the extracted cCTG parameters, Delta Index, Short Term Variability (STV), Long Term Variability (LTV), Acceleration and Deceleration Phase Rectified Slope (APRS, DPRS) values were lower in the late FGR participants compared to the control group. In the FGR cohort, Delta, STV, APRS, and DPRS were found different when stratifying by MCA_PI (MCA_PI <5th centile or > 5th centile). STV and DPRS were the only parameters to be found different when stratifying by (UA_PI >95th centile or UA_PI <95th centile). Additionally, we measured the predictive power of cCTG parameters toward the identification of associated Doppler measures using figures of merit extracted from ROC curves.The AUC of ROC curves were accurate for STV (0,70), Delta (0,68), APRS (0,65) and DPRS (0,71) when UA_PI values were > 95th centile while, the accuracy attributable to the prediction of MCA_PI was 0.76, 0.77, 0.73, and 0.76 for STV, Delta, APRS, and DPRS, respectively.An association of UA_PI>95th centile and MCA_PI<5th centile with higher risk for NICU admission, was observed, while CPR < 5th centile resulted not associated with any perinatal outcome. Values of STV, Delta, APRS, DPRS were significantly lower for FGR neonates admitted to NICU, compared with the uncomplicated FGR cohort.ConclusionsThe results of this study show the contribution of advanced cCTG parameters and fetal Doppler to the identification of late FGR and the association of those parameters with the risk for NICU admission.Trial registrationRetrospectively registered.

Multi-Detector Heart Rate Extraction Method for Transabdominal Fetal Pulse Oximetry.

Intrapartum fetal well-being assessment relies on fetal heart rate (FHR) monitoring. Studies have shown that FHR monitoring has a high false-positive rate for detecting fetal hypoxia during labor and delivery. A transabdominal fetal pulse oximeter device that measures fetal oxygen saturation non-invasively through NIR light source and photodetectors could increase the accuracy of hypoxia detection. As light travels through both maternal and fetal tissue, photodetectors on the surface of mother's abdomen capture mixed signals comprising fetal and maternal information. The fetal information should be extracted first to enable fetal oxygen saturation calculation. A multi-detector fetal signal extraction method is presented in this paper where adaptive noise cancellation is applied to four mixed signals captured by four separate photodetectors placed at varying distances from the light source. As a result of adaptive noise cancellation, we obtain four separate FHR by peak detection. Weighting, outlier rejection and averaging are applied to these four fetal heart rates and a mean FHR is reported. The method is evaluated in utero on data collected from hypoxic lamb model. Ground truth for FHR is measured through hemodynamics. The results showed that using multi-detector fetal signal extraction gave up to 18.56% lower root-mean-square FHR error, and up to 57.87% lower maximum absolute FHR error compared to single-detector fetal signal extraction.

An Unusual Monochorionic Pregnancy.

An Unusual Monochorionic Pregnancy.

Obstetrician involvement in planned midwife-led births: a cohort study in an obstetric department of a University Hospital in Switzerland

BackgroundHealthy women with low risk singleton pregnancies are offered a midwife-led birth model at our department. Exclusion criteria for midwife-led births include a range of abnormalities in medical history and during the course of pregnancy. In case of complications before, during or after labor and birth, an obstetrician is involved. The purpose of this study was 1) to evaluate the frequency of and reasons for secondary obstetrician involvement in planned midwife-led births and 2) to assess the maternal and neonatal outcome.MethodsWe analyzed a cohort of planned midwife-led births during a 14 years period (2006-2019). Evaluation included a comparison between midwife-led births with or without secondary obstetrician involvement, regarding maternal characteristics, birth mode, and maternal and neonatal outcome. Statistical analysis was performed by unpaired t-tests and Chi-square tests.ResultsIn total, there were 532 intended midwife-led births between 2006 and 2019 (2.6% of all births during this time-period at the department). Among these, 302 (57%) women had spontaneous vaginal births as midwife-led births. In the remaining 230 (43%) births, obstetricians were involved: 62% of women with obstetrician involvement had spontaneous vaginal births, 25% instrumental vaginal births and 13% caesarean sections. Overall, the caesarean section rate was 5.6% in the whole cohort of women with intended midwife-led births. Reasons for obstetrician involvement primarily included necessity for labor induction, abnormal fetal heart rate monitoring, thick meconium-stained amniotic fluid, prolonged first or second stage of labor, desire for epidural analgesia, obstetrical anal sphincter injuries, retention of placenta and postpartum hemorrhage. There was a significantly higher rate of primiparous women in the group with obstetrician involvement. Arterial umbilical cord pH < 7.10 occurred significantly more often in the group with obstetrician involvement, while 5′ Apgar score < 7 did not differ significantly. The overall transfer rate of newborns to neonatal intensive care unit was low (1.3%).ConclusionA midwife-led birth in our setting is a safe alternative to a primarily obstetrician-led birth, provided that selection criteria are being followed and prompt obstetrician involvement is available in case of abnormal course of labor and birth or postpartum complications.

Challenges of Developing Robust AI for Intrapartum Fetal Heart Rate Monitoring.

Background: CTG remains the only non-invasive tool available to the maternity team for continuous monitoring of fetal well-being during labour. Despite widespread use and investment in staff training, difficulty with CTG interpretation continues to be identified as a problem in cases of fetal hypoxia, which often results in permanent brain injury. Given the recent advances in AI, it is hoped that its application to CTG will offer a better, less subjective and more reliable method of CTG interpretation. Objectives: This mini-review examines the literature and discusses the impediments to the success of AI application to CTG thus far. Prior randomised control trials (RCTs) of CTG decision support systems are reviewed from technical and clinical perspectives. A selection of novel engineering approaches, not yet validated in RCTs, are also reviewed. The review presents the key challenges that need to be addressed in order to develop a robust AI tool to identify fetal distress in a timely manner so that appropriate intervention can be made. Results: The decision support systems used in three RCTs were reviewed, summarising the algorithms, the outcomes of the trials and the limitations. Preliminary work suggests that the inclusion of clinical data can improve the performance of AI-assisted CTG. Combined with newer approaches to the classification of traces, this offers promise for rewarding future development.

Fetal heart rate estimation by non-invasive single abdominal electrocardiography in real clinical conditions

Fetal heart rate (FHR) is the main feature for monitoring fetal well-being as recommended by the International Federation of Gynecology and Obstetrics (FIGO). The ultrasound based cardiotocography (CTG) is nowadays the world-wide non-invasive clinical reference technique for intrapartum FHR monitoring, as stated by FIGO. However, some limitations of CTG have justified the interest for alternative solutions, based on abdominal electrocardiography (ECG). Their aim is to extract a fetal ECG signal (fECG), from which R peaks are detected to deduce FHR. Nevertheless, most published methods require a large number of abdominal sensors, which is not suitable for an expected use in real clinics. A novel methodology using a single abdominal ECG derivation is then investigated for FHR estimation in real clinical conditions.After maternal ECG attenuation, a source-filter model is considered to characterize the resulting fetal signal. Based on a non-negative matrix factorization of its spectrogram, the fundamental frequency of the source part is estimated, corresponding to FHR. Validation of the proposed FHR estimation is carried out on a real clinical database.Compared to a selection of other FHR estimation methodologies, our proposition presents the best performance in terms of reliability and similarity to the reference CTG. Evaluated for 8 subjects, corresponding to a total of 167 min of recordings, the mean ratio of outliers is lower than 25%. These good results in real clinical conditions makes the proposed methodology a promising solution for use in routine practice by hospital departments.

Use of Methadone Maintenance Therapy for Opioid Use Disorder in Pregnancy.

Use of Methadone Maintenance Therapy for Opioid Use Disorder in Pregnancy.